The Psalms begin the Writings or Hagiographa in the three-fold division of the Law of Moses, the Prophets, and Writings of Hebrew Scripture. In the four-fold division of the Greek Septuagint, the Latin Vulgate, and the Christian Old Testament of the Bible, the Psalms are part of the Wisdom Literature, which includes in the following order: the Books of Job, Psalms, Proverbs, Ecclesiastes, and the Song of Songs. The Greek Septuagint and Latin Vulgate also included the Books of Wisdom and Sirach.
The Hebrew Psalms number 150, while the Dead Sea Scrolls as well as the Greek Septuagint Old Testament both contain Psalm 151 of David. The numbering of Psalms often differ by one, the Hebrew Psalter being one more than the Greek Septuagint and Latin Vulgate. The numbering here follows the original Hebrew. The Psalms are generally of three types: laments, both individual and communal; hymns; and songs of thanksgiving. Others are classified as royal psalms, some wisdom psalms, and others defy classification.